Becoming Comfortable with your Skin
Discovering the layers
Do you know what the biggest organ in your body is? not your brain nor your large intestine. Give up? The subject of this book may have given the answer away, so I’ll suspend any further guesswork and tell you: It’s your skin. That’s right; skin is an organ (just like your heart, lungs, and liver). And if you spread out the skin of the average adult it would measure 20square feet, about the size of a twin-sized bed sheet! In this chapter, I cover the ins and outs of your skin so that you can see just where your acne originates. I acquaint you with the many functions that your “largest organ” performs and tell you a little about how to take care of it.
Exploring Your Largest Organ
You may not really think of the skin as an organ, like the heart and lungs. To many people, skin seems more like a simple cover to prevent their insides from falling out. An organ is a somewhat independent part of the human body that performs a specific function. Once you know that, you can see that the skin is an organ, because it performs the following specific functions (in addition to others): Protects your body from infection Serves as a waterproof barrier between you and the outside world Shields you from the sun’s harmful rays Provides cushioning like a shock absorber that defends you from injury Insulates your body and keeps your temperature at 98.6 degrees Fahrenheit (37 degrees Celsius) Acts as an energy reserve Alerts you to potential harm through your sensations of touch and pain Repairs itself (that’s why cuts heal) and Produces vitamin D.
Because your skin has so many functions, you will not be surprised to discover that it also has a rather complicated structure with many working parts. It contains hairs that have their own oil glands and tiny muscles — I’ll bet that you didn’t know that hairs have muscles! Your skin has sensory nerves — hot, cold, touch,
and pressure receptors. It also is home to blood vessels, lymph vessels, and sweat glands. Plus, your skin has microscopic pigment producing cells, cells that work on your immunity, as well as cells that protect and replace themselves. Human skin is made up of three layers. First come the top two layers — the epidermis (the outside layer of skin that you can see) and the dermis (located directly beneath the epidermis)
Then comes the third, bottom fatty layer that the epidermis and dermis rest upon, which is called the subcutaneous layer. In the sections that follow, I take you on a guided tour of each of these layers
Rising above it: your Epidermis that is.
Your epidermis is really strong. Most of the cells that make up the epidermis are called keratinocytes. Keratinocytes are filled with an exceptionally tough, fibrous, protein known as keratin. The Latin term for cells is “cytes.” Therefore, keratino-cytes, by definition, are cells (cytes) comprised of keratin. Just as your skin has more than one layer (epidermis, dermis, and subcutaneous layer), the epidermis itself has three layers. Within these layers, there’s constant cellular motion going on.
The Outer layer: The outermost layer of the epidermis is known as the stratum corneum, or more memorably the horny layer. This layer provides your body with a durable coat that protects the rest of the cells from damage, infection, and from dehydrating. This horny layer is actually made up of dead skin cells (Your hair and nails are also made of dead cells) So when you look at your skin, you’re really seeing skin that is dead. These deceased skin cells only stick around for a little while, they flake off when you wash, scratch yourself, go shopping, sit in class, fall asleep, basically, all the time. In fact, every minute of the day we lose about 30,000 to 40,000 dead skin cells off the surface of our body, which is where the vast majority of dust comes from but that is another story.
Middle layer: This layer is known as the stratum spinosum. The cells in this layer looked kind of spiny to the scientists who first described them.
Inner layer: Known as the basal layer, the inner layer is like aproduction facility for the new skin cells (keratinocytes) that eventually make their way up through the stratum spinosum to the outer stratum corneum to replace the dead older cells you lose from the surface. The keratinocytes in the basal layer stand up like little soldiers
at attention on what’s called the basement membrane, a barrier that separates the epidermis from the dermis; this joins the epidermis and dermis together. The keratinocytes are kept alive by the underlying dermis — which serves as their blood supply because the epidermis has no blood supply of its own. But their upward journey carries them farther away from their supply lines, and as they approach the top, they begin to die. By the time they’ve
reached the outer layer of the epidermis, they’ve lost virtually all of their cellular contents except for tough keratin fibres and other solid proteins. Even as they dry up and die, they become much more resilient and durable and become the flattened cells that form the stratum corneum. This one-way trip takes about two weeks to a month to accomplish.
When an injury or an acne pimple penetrates the basement membrane, a scar may result. (covered later)
Scratching the surface
Your dermis, the layer of skin that lies just under your epidermis, has an intimate relationship with your epidermis. It comes equipped with sensory nerves, sweat glands, blood vessels, and hair follicles. It nourishes the epidermis by providing gases such as oxygen and carbon dioxide, which reach the epidermis by diffusing through the basement membrane. The epidermis can’t survive without the dermis, because it has no nerves or blood supply of its own.
Throughout the dermis are collagen and elastin fibres. Collagen is aresilient protein that provides rigidity and strength to the dermis. Elastin is made of a protein structure that is able to coil and recoil like a spring. This protein is what gives the skin its elasticity. Also located in the dermis is the hair follicle. A hair follicle is a hair-containing canal; a tube-shaped sheath that surrounds the part of the hair that is under the skin. It’s located in the epidermis and the dermis. Blocked hair follicles are often at the root of the acne problem. In fact, it seems like the hair follicle is
the central focus of this entire book! (To read a detailed description of how a follicle becomes blocked and a pimple forms, Sties, boils, shaving bumps — I could go on and on — all have their origins in the hair follicle. These are conditions that folks often mistake for acne.
Fat cells known as lipocytes reside in the subcutaneous layer. Talk of the subcutaneous layer will be brief because as far as acne is concerned, there is little going on here.
Just the stats on skin Ma’am
Skin fact to impress your friends and family:
Skin is your heaviest organ. It accounts for about 15 percent of your body weight. The skin of a 400-pound sumo wrestler can weigh in at as much as 60 pounds!
The skin of an average adult woman weighs about 20 pounds.
The thickness of the average epidermis varies from 0.5 millimetres on your eyelids to 4.0 millimetres or more on the palms of your hands and the soles of your feet.
You produce a totally new epidermis about every 30 days!
Most of the dust in your classroom or bedroom is made of tiny fragments of human skin. In just one minute, 30,000 to 40,000 skin cells fall unseen from the surface of your body. That means you lose around 15 million or so skin cells in one year. (Wow that is a dusty wrestler’s bedroom!)
Your dermis is several times thicker than the epidermis and is particularly thick on the upper back.
“Goosebumps” come from tiny muscles called erector pili. These muscles attach to each of our hairs and make them stand at attention when we’re cold or afraid. We can see this phenomenon on a frightened cat whose fur stands on end. It’s meant to make kitty look bigger and scarier to other animals. And when we had more body hair during the Stone Age, it probably did the same for us.
You have about 3 to 5 million hairs on your body.
Your nails grow faster in warmer weather. They grow at a rate of 0.5 to 1.2 millimetres
per day, with fingernails growing faster than toenails